Substituted (4-benzimidazol-2-ylmethylamino)benzamidines, particularly 1-methyl-2-[N-[4-(N-n-hexyloxycarbonylamidino)phenyl]aminomethyl]benzimidazol-5-yl-carboxylic acid-N-(2-pyridyl)-N-(2-ethoxycarbonylethyl)amides are already known from International Patent Application WO 98/37075 as active substances with a thrombin-inhibiting and thrombin time-prolonging activity.
The main field of indications for the compound of chemical formula I is the postoperative prevention of deep vein thrombosis.
In WO 98/37075 it is proposed to prepare substituted (4-benzimidazol-2-ylmethylamino)-benzamidines by reacting the corresponding, substituted (4-benzimidazol-2-ylmethylamino)benzonitriles with ammonia. This method is very onerous in terms of production costs and results in a high load of acids requiring disposal.
The aim of the present invention was to indicate an alternative method of preparing the substituted (4-benzimidazol-2-ylmethylamino)benzamidines, by which this onerous stage of the production process could be avoided.